Method and apparatus for self-pressurizing monofuel system



D. C. PRINCE Nov. 1 1960 METHOD AND APPARATUS FOR SELF-PRESSURIZING MONOFUEL SYSTEM Filed Aug. 2 1957 3 Sheets-Sheet 1 FIG.

1N VENT OR. DAVID C. PPM/C E BY M Ja 4 W A 7' TUBA/5Y6.

Nov. 1, 1960 D. c. PRINCE 2,958,193

METHOD AND APPARATUS FOR SELF-PRESSURIZI'NG MONOFUEL SYSTEM Filed Aug. 2'; 1957 3 Sheets-Sheet 2 I F IG. 3.

7 2a A 270 T 327: 50a. 27 7/26 ll 40, i 1 ".37 I. 29/ i 1 Z9! /3/ 2.94 i T I] 32 2M 51 14 A 10 g 25 30 N I 32 .70 I v INVENTOR. 0/! W0 6. PRINCE D. C. PRINCE NOV- 1, 1960 2 958,193 METHOD AND APPARATUS FOR SELF-PRESSURIZING MONOFUEL SYSTEM Filed Aug. 2, 1957 3 Sheets-Sheet 3 FIG. 5.

FIG. 4.

INVENTOR. 0A W0 6'. PRINCE A TTOPA EYSI METHOD AND APPARATUS FOR SELF-PRES- SURIZING MONOFUEL SYSTEM David C. Prince, 50 Washington Ave, Schenectady 5, N.Y.

Filed Aug. 2, 1957, Ser. No. 675,884

8 Claims. (Cl. 60--39.46)

This invention relates to a method and apparatus for supplying liquid monofuel under pressure generated by the catalytic decomposition of the fuel itself.

Liquids known as monofuels are presently in use in rockets and other devices. Hydrogen peroxide is one of the monofuels of this class of fuels which, in the presence of a suitable catalyst, such as silver, decompose with a large liberation of energy into gaseous oxygen and superheated steam. If the energy of decomposition is used directly, the use of the monofuel is termed primary. If the by-product, gaseous oxygen, is used only to support the combustion of a hydro-carbon fuel, the use of the monofuel is termed secondary.

In many instances, it is desirable to provide the liquid monofuel under pressure from a reservoir directly to a reaction chamber for primary uses or to an intermediate decomposer for secondary uses, the gaseous products of which are thereafter sent to a reaction chamber. Heretofore, a pressure generating apparatus has been provided separate and remote from the monofuel reservoir and utilizing gases such as nitrogen, air or oxygen to act as the pressure means to drive the monofuel from the reservoir into the monofuel consuming apparatus. These monofuel systems have serious disadvantages and limitations, among which are the very complex control apparatus needed to transmit the re motely generated pressure gases to the fuel reservoir and the deleterious effects of the pressure gases on the chemically different monofuels. v

The principal objects of the present invention are to provide an improved monofuel feeding system which will generate feeding pressures within the reservoir of the monofuel, using a portion of the monofuel itself; to control automatically the self-pressurized supply of fuel from the reservoir; and to simplify the construction and method of operation of monofuel feed systems.

In the practice ofthe invention, the liquid monofuel is fed from a closed reservoir while catalytically decomposing a portion of the monofuel to form a gas as a decomposition product. This gas is collected in the reservoir above the liquid level of the monofuel therein to create a gas 'pressure' acting to expel the liquid through its outlet from the reservoir. The rate of the catalytic decomposition is controlled in accordance with variations in the gas pressure within the reservoir, to maintain this pressure substantially constant. Thus, the liquid monofuel is discharged through its outlet at a substantially constant rate under pressure generated fro the monofuel itself.

A monofuel feeding apparatus made according to the invention comprises a closed vessel forming a reservoir for the liquid monofuel, the vessel having a liquid monofuel outlet passage and a catalyst chamber both communicating with the reservoir. A valve controls the flow of liquid monofuel to the catalyst chamber where it decomposes at least partially under the action of the catalyst, which may be silver when the hydrogen per- States Patent Patented Nov. 1, 1960 oxide is used as the monofuel. This decomposition results in formation of a gas (oxygen and steam in the above example), which is allowed to escape through a suitable passage into the reservoir, thereby building up the aforementioned gas pressure above the liquid level. The control valve for the catalyst chamber is operatively connected to a device, such as a bellows, responsive to variations in this gas pressure, so that the pressure is maintained substantially constant. Preferably, the outlet passage for the liquid monofuel has a cut-off valve which, in its closed or off position, insures that the control valve for the catalyst chamber will be closed irrespective of the gas pressure in the reservoir.

In the preferred construction, the cut-off valve, the control valve for the catalyst chamber and the pressureresponsive device are included in a unitary assembly forming the catalyst chamber and the monofuel outlet passage, the assembly being readily applied to the closed vessel forming the monofuel reservoir.

These and other features of the invention will be apparent from the following description of a specific example as illustrated by the drawings.

In the drawings:

Fig. 1 is a vertical view partly in section of a spherical vessel forming a reservoir for the monofuel and containing the automatic pressure control assembly of the invention;

Fig. 2 is a view of the valve taken through sectional line 2-2 of Fig. 1, in the on position;

Fig. 3 is a vertical sectional view of the automatic pressure control assembly in the manually off position;

Fig. 4 is a view similar to Fig. 3 but with the assembly in the on position before build-up of pressure;

Fig. 5 is a view similar to Fig. 3 in the on position after build-up of pressure.

In the drawings, like reference characters refer to identical parts.

The embodiment of the invention chosen for the purpose of illustration comprises a generally spherical, rigid and pressure-tight vessel 10 forming a monofuel reservoir (Fig. 1). A monofuel such as hydrogen peroxide (H 0 is introduced into the reservoir through a threaded opening in the upper wall portion 13 of the vessel 10. The reservoir is shown filled with the monofuel to the level 11.

A filler plug 12 is screwed into the threaded opening in the enlarged wall portion 13 after the monofuel has been introduced into the reservoir through this opening. The filler plug 12 includes a safety valve for automatically relieving pressures within the reservoir above a. prescribed critical value. Such a valve may include a ball 14 smoothly seated on a seat provided in the lower portion of an escape chamber 15. Chamber 15 is vented to the ambient by passageways 16 and 17 and communicates with the reservoir through passageway 15a. An adjusting screw 18 provides for pressure adjustment of a spring 19 which urges the ball 14 against its seat. In operation, the ball 14 remains seated in the valve chamber 15 to prevent fluids within reservoir 10 from escaping through passages 15a, 16-17 as long as the fluid pressures in the reservoir are less than the downward force exerted by spring 19 on ball 14. When the internal pressure exceeds the spring pressure, the ball 14 is forced away from its seated position, allowing the high pressure fluids to escape to the ambient through chamber 15 and vents 16 and 17.

. An automatic pressure generator and regulator assembly 26 is screwed into a threaded hole provided in an enlarged wall portion 25 at the bottom of the vessel 10. The assembly 26 is of generally cylindrical shape and has threads on a portion of its outer surface for engagement with the threads in the hole of wall portion 25. Thus, the assembly 26 may be screwed into or out of the vessel as desired for maintenance or replacement.

'The assembly 26, as shown in Figs. '25, comprises a housing or casing 26a, the interior of which is divided into a series of spaces 27, 28, 29 and 30. The upper space 27 is generally cylindrical and is provided with vents in the .form of lateral passageways 27a and 27b through the wall of vessel 26a. Space 29 is shaped generally as an oblong cavity and is provided with vents in the form of lateral passageways 29a and 29b for interconnecting space 2? with the interior of the vessel 10.

The lowermost space 30 is of reduced diameter except for an enlarged portion which receives a manually operable cock-valve 31. The selected position of the cockvalve '31 limits the movements of a valve associated with the decomposition on the chamber formed by space 28. The cock valve 31 also operates as an open-close valve in the discharge conduit formed by space 30. Details of the valves will be explained presently.

At its lower end, the housing 26a is provided with external threads 30:: for connection to a conduit (not shown) which conducts the liquid fuel to the consuming apparatus, such as the reaction chamber of arocket engine.

Cock-valve 31 is generally cylindrical and is rotatably mounted in a cylindrical recess of passageway 30. The axis of'rotation of cock-valve 31 is perpendicular to the longitudinal axis of the passageway 30. A hole 32 is provided through the cock-valve 31, equal in diameter to the diameter of passageway 30 (Figs. 3-5). A slot iscut in the cock-valve 31 to receive a heart-shaped cam 33. The cock is turned by the handle 31a.

A rod 34 is movable axially in the cylindrical housing 26a ancl is held against lateral displacement from the housing axis by means of a spider 26b secured in the upper end of passage 30 andby connection of the upper end of the rod to a pressure sensitive bellows 35. The bellows 35 is mounted in a cap 36 which is telescopically movable within the uppermost space 27 of the housing 26a. Integrally formed on rod 34 are two valves 37 and 38 which respectively seat into the constricted portions or valve seats 40 and 41. The lower end of rod 34 rests upon the cam surface 33 of cock-valve 31, under certain conditions to be described presently.

Within the space 28 is a silver plated screen 42 serving as a catalyst for causing the decomposition of a monofuel such as hydrogen peroxide.

In operation, the reservoir formed by vessel 10 (Fig. 1) is assumed to be filled with hydrogen peroxide approximately to the level 11 or at least to a level allowing sufficient space for gas pressure to develop about the surface of the peroxide. It will be further assumed that the confined pressure initially is atmospheric. The description which follows is more particularly related to Figs. 3, 4 and 5 showing the various operating positions of the selfgenerating pressure feeding apparatus of the invention.

In Fig. 3, assembly 26 is shown in its 01f or closed position. Cock-valve 31 is shown rotated so that the passageways 32 are perpendicular to the passageway 30, thereby preventing any fluid from passing therethrough. Rod 34 is shown resting on the cam surface 33 of valve 31, so that the rod is held in its most extreme upward position. .In this position, the valves 37 and 38 are shown fully seated respectively in the valve seats 40 and 41. Bellows 35 is shown expanded because the pressure of the fluid within the reservoir is at its least value, assuming the initial atmospheric pressure. The telescoping cap 36 serving as a centering guide for the bellows 35 and rod 34 is shown raised from its fully seated position against the upper end of housing 26a.

In Fig. 4, the assembly 26 is shown with the cock-valve 31 rotated to its full on or open position so that the passage 32 is a continuation of the passageway 30, thereby allowing monofuel to pass from the reservoir through the passageways 29a and 29b into the space 29 and thence downwardly through .passagewy 30 to the connecting conduit (not shown). The rod 34 is now seen to have dropped into its lowermost position against the central recessed portion of cam surface 33, allowing the rod to unseat the valve portions 37 and 38 from their seats and to seat the bellows cap 36 against the top of housing 26a. The hydrogen peroxide is thus permitted to flow by way of passages 27a-27b and 29a--29b into the space 28 and contact the silver-plated screen 42.

The monofuel, hydrogen peroxide, thus decomposes in the space 28 to produce gaseous hydrogen and superheated steam, which are permitted to escape upwardly through passageways 27a and 27b and collect above the surface level 11 of the liquid hydrogen peroxide. The passages 2a29b also provide an escape path leading to the accumulatingspace above the liquid level 11. The pressure above the liquid peroxide thus builds up rapidly in the vessel 10. This increased pressure is transmitted by the liquid through passages 27a--27b to the chamber 27 where it acts to contract the bellows 35, the cap 36 remaining firmly seated due to the greater elTective area of its upper surface as compared with its lower surface and also due to the weight of the parts 34-'38. Upon contraction of bellows 35, the rod 34 is drawn away from the cam surface 33 and the valves 37 and 38 become seated in the valve seats 40 and 41, thereby shutting off the flow of hydrogen peroxide into the reaction chamber 28. The position of the various elements of the assembly in this stage of the operation is shown in Fig. 5. As long as the pressure within the reservoir 10 is at a prescribed level (depending upon the response characteristics of the pressure-sensitive bellows 35), the valves 37 and .38 will remain in their fully seated positions and prevent further decomposition of the monofuel due to the 'catalyst in chamber 28. If the pressure within the reservoir is reduced, as by the cooling of the gaseous byproducts or by reduction of the liquid peroxide level, the bellows 35 will expand and thus lower the valves 37 and 38, allowing additional peroxide to flow into the decomposition chamber 28 .to restore the pressure to the prescribed level.

Accordingly, as long as the cock-valve 31 is set to permit fuel to flow from the reservoir 10 through the passage way 30, the apparatus of the invention automatically generates'the pressure necessary to maintain the flow at the selected rate. When desired, the operation is halted by turning the cock-valve 31 to its oil position shown in Fig. 3.

As an automatic self-pressurizing fuel supply, the apparatus of the invention may be used in rocket engines as a pressurized source of fuel in primary or secondary applications, or in auxiliary starting devices in which a large amount of power may be required for short times, such asin starting jet engines and the like. Because of its simplicity of construction and lightness of weight, the new apparatus may be used to particular advantage as a high-pressure supplyof peroxide for aircraft engines.

As will be apparent from the foregoing the cock-valve 31, by reason of its cam surface 33, forms a means for moving the bellows device 35 and valve 37--38 as a unit relative to the housing 26a to close the valve irrespective of the pressure in the vessel 10 above the liquid level of the monofuel. That is, if valve 3738 is open (fully as in Fig. 4, or only partly), rotation of cock-valve 31 from its on position (Fig. 4) to its ofi position (Fig. 3) will cause the cam means 33 to lift valve rod 34 and thereby close valve 37-38, even if bellows 35 is expanded as shown in Figs. 3 and 4.

I claim:

1. Apparatus for feeding a liquid monofuel, which comprises a closed vessel forming a reservoir for the monofuel, the vessel having a liquid monofuel outlet passage and a catalyst chamber communicating with the reservoir, a valve for controlling the flow of monofuel from the reservoir into said chamber, a catalyst in said chamber for decomposing monofuel therein to form a gas as a decomposition product, there being an escape passage for said gas leading into the reservoir, whereby the gas collects in the reservoir above the liquid level of the monofuel and creates a pressure acting to expel the liquid monofuel through said outlet passage, a device responsive to variations in said pressure and operatively connected to the valve for maintaining said pressure substantially constant, a cut-01f valve in said outlet passage, said last valve being movable between on and ofi positions, and means responsive to movement of said last valve to its on position for opening said first valve to initiate flow into the catalyst chamber.

2. Apparatus according to claim 1, in which said pressure-responsive device is a bellows.

3. Apparatus according to claim 1, in which the catalyst chamber leads to said outlet passage.

4. Apparatus according to claim 1, in which said outlet passage communicates with the reservoir by way of the catalyst chamber and also independently of said chamber.

5. Apparatus for feeding a liquid monofuel, which comprises a closed vessel forming a reservoir for the monofuel, a housing in the vessel forming a catalyst chamber and below said chamber a liquid monofuel outlet passage leading from the reservoir, said chamber having an inlet through which monofuel is adapted to enter the chamber from the reservoir and also having an outlet below said inlet, a catalyst in the chamber for decomposing rnonofuel flowing therethrough to form a gas as a decomposition product, said gas being adapted to escape to the reservoir through at least one of said inlet and outlet and collect in the reservoir above the liquid level of the monofuel, thereby creating a pressure acting to expel liquid monofuel from the reservoir through said outlet passage, a valve in the housing for controlling the flow of monofuel through the chamber, and a device responsive to changes in said pressure and operatively connected to the valve for maintaining the pressure substantially constant.

6. Apparatus according to claim 5, comprising also means for moving said device and valve as a unit relative to the housing, to close the valve irrespective of said pressure.

7. Apparatus according to claim 5, comprising also a cut-off valve in said outlet passage, said last valve being movable between on and off positions, and means responsive to movement of the cut-off valve to its off position for moving said device and first valve as a unit relative to the housing, to close said first valve irrespective of said pressure.

8. Apparatus according to claim 5, comprising also a cut-off valve in said outlet passage, said last valve being movable between on and oil positions, a rod interconnecting said device and the first valve, and a cam engageable with the rod and movable with the cut-off valve to its oil position for moving said device and first valve as a unit relative to the housing, to close said first valve irrespective of said pressure.

References Cited in the file of this patent UNITED STATES PATENTS 1,588,885 Hart -June 15, 1926 2,852,916 Hearn et a1 Sept. 23, 1958 2,858,672 Clark Nov. 4, 1958 FOREIGN PATENTS 200,758 Australia Jan. 27, 1956 

